Do I need fasteners or hardware to install this?

Fasteners are not included with the assembly. You'll use the factory bolt holes on your door panel — grab the bolts from your old regulator or pick up a hardware kit rated for automotive door applications.

Can I swap just the motor, or do I have to replace the whole regulator?

This comes as a complete assembly, so motor and regulator are paired. If only the motor failed, you could potentially source a motor-only kit separately — but this unit is designed as a bolt-in replacement for the entire assembly.

What if the window doesn't operate smoothly after install?

Check that all bolts are tight at the door frame attachment points and that the regulator tracks cleanly in the window channel. A binding track or loose mounting will cause resistance. If the motor still won't run after that, test the door wiring harness — a bad connector can kill power to the assembly.